1. Field of the Invention
The present invention relates to arthroscopic surgical methods and instruments and, more specifically, to a flip retrograde cutting instrument and methods of retrograde repairs and reconstructions.
2. Description of the Related Art
During arthroscopic surgery, a small incision is made in the skin covering the arthroscopic site or joint, and a cannula is inserted in the incision to provide a pathway for surgical instruments to be placed in the joint and manipulated through arthroscopic visualization. Surgical instruments inserted through cannulas must be long and thin—this presents limitations on instruments for cutting tissue, as the diameter of the cannula ordinarily limits the width of the cutting implement.
Retrograde drilling of sockets and tunnels for ACL reconstruction is known and described, for example, in U.S. Patent Application Publication No. 2007/0233138, entitled “Method and Apparatus for ACL Reconstruction using Retrograde Cutter”, the disclosure of which is incorporated by reference herein. In such a method, sockets in bone created by retrograde cutting. A rotary cutter, mounted onto an insertion post of a guide, is inserted through an anteromedial portal into the knee joint. A drill pin is drilled through the tibia and advanced until it contacts and engages a cannulation in the rotary cutter on the guide. Further rotation of the drill pin disengages the rotary cutter from the guide. The retrograde drill pin is then retracted and simultaneously rotated for retrograde cutting of a socket or tunnel of desired depth in the tibia. A similar method can be used for drilling a femoral socket or tunnel. A need exists for a surgical cutting instrument that can be used arthroscopically for retrograde drilling of tunnels or sockets in bone without requiring a rotary cutter and drill pin. As with all arthroscopic instruments, the surgical cutting instrument must be configured for insertion through a narrow cannula, but able to cut a relatively wide tunnel or socket.
A need also exists for a surgical cutter that is stable during knee arthroscopy and that provides drilling of femoral and tibial sockets or tunnels independently of one another and minimizes incisions of distal cortices and reduces intraarticular bone fragmentation of tunnel rims.